Dielectrophoretic manipulation of particles on a microfluidics platform with planar tilted electrodes

Cell/particle separation enabled by lab-on-a-chip (LOC) devices has been a promising solution for separating target cells from the body fluids. Understanding the effects of fabrication and performance parameters on the separation efficiency can further advance applications of such devices in life sciences. This study presents a parametric study on the displacement of the cell-representative polystyrene particles in dielectrophoresis (DEP) based microseparators. The proposed device includes slanted planar interdigitated electrodes to apply a lateral DEP force on the particles. The effect of fabrication parameters (i.e., the channel length and width, and the deflection angle of the electrodes), as well as operational factors (i.e., the volumetric throughput and particle size) on the DEP-induced displacement, are studied. The results show that the volumetric throughput has the most contribution to the position of the particles. Among the geometrical parameters, the channel length is found to be the most effective factor in the particles position, while the effect of the channel width is shown to be negligible. The device was also tested with NIH 3T3 mouse fibroblast cells, which exhibited the same behavior. The results of this research render the desired separation performance to be attained via the design of low-angle slanted electrodes alongside with a balance between the volumetric throughput and the length of the DEP region. These findings lead to a successful size-selective sorting or focusing of 5 kmi-15 km particles, which can provide valuable insights into the design of microfluidic platforms to selectively separate different cell types in biofluids.